In recent years, in consideration of the environment, attention has been focused on a hybrid vehicle, an electric vehicle or the like that uses electric power from a battery and the like to drive a driving wheel.
Particularly, attention has been focused in recent years on wireless charging by which the battery can be charged in a contactless manner without using a plug and the like in the aforementioned electrically powered vehicle having the battery mounted thereon. Various types of contactless charging methods have been suggested recently, and the technique of using the resonance phenomenon to transfer electric power in a contactless manner has been particularly in the spotlight.
For example, a noncontact power transmission device described in Japanese Patent Laying-Open No. 2010-268660 includes a resonator, and this resonator includes a self-resonant coil and a bobbin having an outer circumferential surface to which the self-resonant coil is attached.